It is known in the art to radiate one or more signals from an antenna using a patch launcher and a polarizer in combination. However, the components are individual elements that must be interfaced with each other causing potential problems with the antenna system.
The individual elements used in combination to radiate signals add unwanted mass to the antenna system. Additionally, the elements must be individually joined, or interfaced which requires more assembly time, thereby adding cost to the antenna system. There are manufacturing tolerances for each of the individual components whereby each component introduces a small amount of reflection. The reflections are cumulative and degrade electrical
Optimum performance for a radiating element requires a minimum separation distance which is not possible with individual components used in combination as in the prior art. Additionally, the individual components require attachments, flanges, etc. for interfacing with each other which adversely affects the efficiency of the radiating element.
It is an object of the present invention to eliminate the drawbacks associated with combining individual components for radiating one or more signals. It is another object of the present invention to optimize performance by achieving a minimum separation distance.
It is yet another object of the present invention to reduce the size of the radiating element resulting in higher operating efficiency and a greater scan angle range. It is a further object of the present invention to provide a single unit that is capable of radiating a signal without the need for a separate patch launcher and polarizer, thereby reducing mass, assembly time, and cost. filters the transmitted signal through a bandpass filter, and converts the linearly polarized signal to a circularly polarized signal, whereby the signal is radiated into free space.
The radiating element of the present invention is a waveguide having a detailed inner structure that transforms the signal, in the manner described above, as the signal passes through the waveguide. The inner structure of the waveguide includes at least one coaxial input at one end. A patch launcher is located at the coaxial input. At a predetermined distance from the patch launcher and inside the waveguide are a plurality of spaced apart circumferential irises that act as a bandpass filter. Also inside the waveguide is a polarizer for converting from linear to circular polarization. One example of a polarizer is a plurality of pin members spaced so that they convert the linearly polarized signal into a circularly polarized signal. Other examples are dielectric slab polarziers and squeeze sections. The end of the waveguide, opposite the end having the coaxial input, is an aperture for allowing the signal to radiate into space.
A more complete understanding of the present invention can be determined from the following detailed description when taken in view of the attached drawings and the claims appended hereto.